From German Pat. No. 294 1935 a clutch is known, which is arranged in conjunction with a torque converter and therefore predominantly serves as shift clutch for the interruption of tractive force. In order to be capable of transferring the highest possible energy, the clutch disks are fed with lubricating and cooling oil from the oil pressure system of the torque converter or the transmission. The oil feed occurs only during the clutching-in procedure and the conformation of the clutch is such that a separate sump cannot be formed. In this manner, the mass of the clutch and the churning losses of the clutch is kept small.
During the sliding phase of the clutching sufficient lubrication must be present in order to limit frictional heat. The frictional heat which arises, however, must be carried away reliably in order to avoid overheating. This has the consequence that a pump with greater capacity must be provided because even at slow rotational speed sufficient lubricating and cooling means are required. As a consequence too much energy is withdrawn from the drive shaft and the apparatus works uneconomically.